Idiopathic environmental intolerances (IEI): myth and reality

The psychogenic theory presupposes that idiopathic environmental intoleranc e (IEI) is an overvalued idea explained by psychological and psychosocial p rocesses. The polysomatic symptoms are amplifications of complaints common to the general population, psychophysiological manifestations of stress and the stress-response, or symptoms of psychiatric clinical syndromes. The ps ychogenic theory is supported by provocation challenge studies which demons trate that appraisals of 'reactions' ar e unreliable and cognitively mediat ed. Clinical studies of IEI cases consistently identify greater incidence o f current and premorbid lifetime psychiatric disorders and co-morbidity wit h functional somatic syndromes that ale fashionable 'diagnoses'. The toxico genic theory presupposes low-level chemical sensitivity or intolerance with out objective signs to a plethora of diverse chemical agents. Symptoms are synonymous with disease and attributions are synonymous with cause. Hypothe ses about physiological processes and mechanisms are implausible and unsupp orted by evidence. Advocates claim this phenomenon is so ephemeral that the principles and methods of toxicology do not apply and that a scientific pa radigm shift is in order. (C) 2001 Elsevier Science Ireland Ltd. All lights reserved.